Mercury switch



MERCURY lSWITCH Original Filed Aug. 20. 192'?v lili.

ve/72272" WM /f, M1

Patented Oct. 4, '1932 UNITED sr-Aras assurez eAraNr ori-ica PAULv x. CRAMBLET, or' wicsLAco, rms, AssIeNoB., BY mnsim ASSIGNMENTS, 'ro MINNEAPOLIS-HONEYWELL REGULATOR COMPANY, or MrNNEAroLIsmNNEso'rA,

' A coRPonA'rroN or' DELAWARE Mim'CURY SWITCH Original application lei August 20, 1927, Serialflo.

for high speed operation and consequently v adapted for use in a sign iasher to control the operation ofthe socalled chasing border of an electric sign, although,of course, also .capable of use in various other diverse applications.

A further object is to provide a mercury switch having a sott glass outer envelope through which the 'electrodes are sealed and which has hard glass sleeves so supported-and mounted within the soft glass outer envelope as to serve the dual purpose of protecting thesoft glass outer envelope from the arcs and of insulating the electrodes with which they are associated from the free body of mercury in the outer envelope when this is desirable during the operation of the switch. l'

A still further object is to provide a mercury switch of the character referred to in the preceding paragraph and wherein the sleeves are mounted in a novel and effective manner on the seals provided for the electrodes.

c bodying. the present invention;

Figure 2 is a view in horizontal section. taken on line 2--2 of Figure I;

Figures 3 and 4 are sectional views similar to Figure 1 and illustrating diierent types of 214,373. Divided and this application filed `iuly 30,

l 1980. `Serial No. 471,651.

l mercury switches which may have a novel as an example, one circuit with which the' switch shown in Figures 1 and 2 may be employed. s

Referring to the drawing and vmore particularly to Figures ,1 and 2, the numeralK 1 designates generally a mercury switch including an outer envelope 2 which may be Iconstructed of soft glass. Electrodes 3, 4, 5, 6 and 7 extend-in through the base of the envelope 2 and are supported in seals 8 which are constitutedby in integralvinward projections or bosses on the base of the soft glass outer envelope. Sleeves 9 surround the .electrodes 3, 4, 5 and 6 and are supported on the seals 8 by annular supporting rings and closures 10 which maybe constituted of insulating asbestos cement or of any other suitable material. These rings 10 serve the dual purpose of closing the lower ends of the sleeves 9 and of providing a yieldable support for these sleeves on the seals 8. rlhe sleeves 9 are of hard glass, quartz or the like, and it is to be understoodI in this connection that in the specification and claims wherever these sleeves are referred to as being of hard glass, other equivalent materials are contemplated. The hard glass sleeves'have a di'erent coeilicient of expansion from that of the soft glass outer envelope but the supporting rings 10 have the property of yielding to accommodate or compensate for'this difference in expansion thereby preventing cracking or breakage. A body of mercury is contained in the outer soft glass envelope and has por tions P filling the wells defined by the sleeves 9 and a free portion F vsurrounding the outside of the sleeves and constantly immersing the electrode 7 which, as shown in Figure 1, is left exposed, that is, without a sleeve.

Asshown in Figure 2, the electrodes 3, 4,

r5 and 6 and the wells defined by their sleeves are arranged in a circular series within the outer envelope and are spaced from the cen-A ter thereof and are located at angular intervals with respect to each other. With a mercury switch of this character if suitable mocov tion is imparted to the outer envelope the free portion F of the body of mercury may be caused to successfully unite with the portions P of the mercury located in the wells surrounding the electrodes 3, 4, 5 and G.

The novel organization of the sleeves with the electrodes and with the outer soft glass envelope is capable of being embodied in varions types of mercury switches.

Figure 3 illustrates amercury switch S having a soft outer lass envelope sha Jed to provide wells W and W. Electrodes E extend into the wells through seals 8 similar to the seals 8 shown in Figure 1. lSleeves 9 having inwardly beveled upper lends are mounted on these seals 8 by means lof mounting rings of asbestos cement, or the like, designated at l0 and similar to the rings 10 of Figure l, except that they. are `somewhat larger to conform to the size of 'the sleeves 9 and as shown are not only interposed between the sleeves and seals but are also interposed between the sleeves and the electrodes. This switch S also includes an electrode G constantly immersed in a body of mercury designated at B, which, in the open position of the switch, is divided into two portions, one within the sleeve 9 and the other within the envelope S, but outside,

the sleeve 9. In the closed position of the switch these two portions of the mercury unite.

In Figure 4 a different type of switch S 1s illustrated, and, as 'in the previous instance, has an electrode H extending in through the outer soft glass envelope through a seal 8a, the seal 8a also serving as a support for the hard glass sleeve 9a through the intermediary of a mounting ring 10a. In this form the body of mercury is designated at B and the electrode constantly immersed in the free portion of the mercury is shown at Gr. A The mercury switch illustrated in Figures l and 2 is especially designed and adapted for use as a sign iasher and because of its capacity te successfully make and break one, two, three, four or more circuits it may be conveniently employed for controlling the socalled chasing border of an electric sign.

In use, the switch shown in Figure l may have its electrodes 3, 4, 5 and 6, respectively,

connected by suitable conductors C with one side of sets of electric lamps designated at 3, 4, 5 and 6. The opposite sides of the lamps are connected to a wire C which leads to the negative source of current. The positive source of current is connected by a wire C with the electrode 7. The free portion F of the mercury switch is of such quantity with respect to the size of the outer envelope and'the spacing of the electrodes as to simultaneously unite with the portions P in three of the wells or sleeves 9 while being spaced from the mercury P in the other well. ,This may be varied, however, to cause the free porand tions F to unite with the mercury in any de- Thus, as illustrated` lamps 6', 5 and 4 but leaves the lamps 3 extinguished. As the mercury travels around the envelope it breaks away from the mercury surrounding the electrodes 6, 5, 4 and 3 in the order named, and thus, the lamps are lighted in such an intermittent order as to give the desired chasing eifect.

The desirable operating motion is imparted to the switch in any suitable manner as, for example, by means fully shown and described in my pending application for mercury switches, filed August 20, 1927, Serial No. 214,373.

The switches shown in Figures 3 and 4 may be operated in any suitable manner as by tipping or rocking or in shuttle fashion.

It is obvious that the switches shown in yFigures 1, 2 and 3 are adapted for pinch or machine sealing inasmuch as the electrodes are sealed in through the envelope or casing of the switch at one end and in spaced relation. Along with this advantage these switches provide the protective elements of arc resistant material which form traps func'- tioning to entrap and confine portions of the mercury while leaving a free portion which unites and divides with the entrapped portions during the operation of the switch.

The invention claimed is:

l. A mercury switch comprising an outer envelope, an inwardly extending boss carried by the outer envelope, an electrode extending in through the boss, and a sleeve surrounding the electrode and the boss, and yieldable means supporting the sleeve on the boss.

2. A mercury switch comprising a casing, spaced electrodes sealed through the casing at one end thereof, a body of mercury in the casing, a separateprotective sleeve surrounding one electrode, a yieldable supporting member and closure between one end of the sleeve and the electrode and its seal, 'said protective sleeve providedy with a trap for entrapping and confining a portion of the body of merc'ury, the remaining free portion of the mercury being adapted to unite with and divide from said entrapped portion upon operation of the switch, said other electrode being constantly immersed in said free portion of the 3. A mercury switch comprising a casing, spaced electrodes sealed through the casing at one end thereof, a body of mercury in the casing, a separate protective element of arc resistant material, yieldable supporting means between one of the electrodes and said protective element, said protective element forming a trap for entrapping and confining a portion of the body of mercury, the remaining free portion of the mercury being adapted to unite with and divide from said entrapped portion upon opera-tion of the switch,

one of said electrodes being immersed in the entrapped portion of the mercury and the other of said electrodes being immersed in the free portion of the mercury,

ln Witness whereof, hereto ax my sig' nature.

.PAUL K. RAMBLET. 

